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vtime-split-lock-and-seqcount.patch 

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2013-07-23 15:45:51 +02:00 committed by Alibek Omarov
parent 9bd27ab4d1
commit 2e358666fe
4 changed files with 46 additions and 25 deletions
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3
include/linux/init_task.h
View File

@ -147,7 +147,8 @@ extern struct task_group root_task_group;
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
# define INIT_VTIME(tsk) \
.vtime_seqlock = __SEQLOCK_UNLOCKED(tsk.vtime_seqlock), \
.vtime_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.vtime_lock), \
.vtime_seq = SEQCNT_ZERO(tsk.vtime_seq), \
.vtime_snap = 0, \
.vtime_snap_whence = VTIME_SYS,
#else

3
include/linux/sched.h
View File

@ -1302,7 +1302,8 @@ struct task_struct {
struct cputime prev_cputime;
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
seqlock_t vtime_seqlock;
raw_spinlock_t vtime_lock;
seqcount_t vtime_seq;
unsigned long long vtime_snap;
enum {
VTIME_SLEEPING = 0,

3
kernel/fork.c
View File

@ -1248,7 +1248,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->prev_cputime.utime = p->prev_cputime.stime = 0;
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
seqlock_init(&p->vtime_seqlock);
raw_spin_lock_init(&p->vtime_lock);
seqcount_init(&p->vtime_seq);
p->vtime_snap = 0;
p->vtime_snap_whence = VTIME_SLEEPING;
#endif

62
kernel/sched/cputime.c
View File

@ -655,37 +655,45 @@ static void __vtime_account_system(struct task_struct *tsk)
void vtime_account_system(struct task_struct *tsk)
{
write_seqlock(&tsk->vtime_seqlock);
raw_spin_lock(&tsk->vtime_lock);
write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
write_sequnlock(&tsk->vtime_seqlock);
write_seqcount_end(&tsk->vtime_seq);
raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_gen_account_irq_exit(struct task_struct *tsk)
{
write_seqlock(&tsk->vtime_seqlock);
raw_spin_lock(&tsk->vtime_lock);
write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
if (context_tracking_in_user())
tsk->vtime_snap_whence = VTIME_USER;
write_sequnlock(&tsk->vtime_seqlock);
write_seqcount_end(&tsk->vtime_seq);
raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_account_user(struct task_struct *tsk)
{
cputime_t delta_cpu;
write_seqlock(&tsk->vtime_seqlock);
raw_spin_lock(&tsk->vtime_lock);
write_seqcount_begin(&tsk->vtime_seq);
delta_cpu = get_vtime_delta(tsk);
tsk->vtime_snap_whence = VTIME_SYS;
account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
write_sequnlock(&tsk->vtime_seqlock);
write_seqcount_end(&tsk->vtime_seq);
raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_user_enter(struct task_struct *tsk)
{
write_seqlock(&tsk->vtime_seqlock);
raw_spin_lock(&tsk->vtime_lock);
write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
tsk->vtime_snap_whence = VTIME_USER;
write_sequnlock(&tsk->vtime_seqlock);
write_seqcount_end(&tsk->vtime_seq);
raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_guest_enter(struct task_struct *tsk)
@ -697,19 +705,23 @@ void vtime_guest_enter(struct task_struct *tsk)
* synchronization against the reader (task_gtime())
* that can thus safely catch up with a tickless delta.
*/
write_seqlock(&tsk->vtime_seqlock);
raw_spin_lock(&tsk->vtime_lock);
write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
current->flags |= PF_VCPU;
write_sequnlock(&tsk->vtime_seqlock);
write_seqcount_end(&tsk->vtime_seq);
raw_spin_unlock(&tsk->vtime_lock);
}
EXPORT_SYMBOL_GPL(vtime_guest_enter);
void vtime_guest_exit(struct task_struct *tsk)
{
write_seqlock(&tsk->vtime_seqlock);
raw_spin_lock(&tsk->vtime_lock);
write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
current->flags &= ~PF_VCPU;
write_sequnlock(&tsk->vtime_seqlock);
write_seqcount_end(&tsk->vtime_seq);
raw_spin_unlock(&tsk->vtime_lock);
}
EXPORT_SYMBOL_GPL(vtime_guest_exit);
@ -722,24 +734,30 @@ void vtime_account_idle(struct task_struct *tsk)
void arch_vtime_task_switch(struct task_struct *prev)
{
write_seqlock(&prev->vtime_seqlock);
raw_spin_lock(&prev->vtime_lock);
write_seqcount_begin(&prev->vtime_seq);
prev->vtime_snap_whence = VTIME_SLEEPING;
write_sequnlock(&prev->vtime_seqlock);
write_seqcount_end(&prev->vtime_seq);
raw_spin_unlock(&prev->vtime_lock);
write_seqlock(&current->vtime_seqlock);
raw_spin_lock(&current->vtime_lock);
write_seqcount_begin(&current->vtime_seq);
current->vtime_snap_whence = VTIME_SYS;
current->vtime_snap = sched_clock_cpu(smp_processor_id());
write_sequnlock(&current->vtime_seqlock);
write_seqcount_end(&current->vtime_seq);
raw_spin_unlock(&current->vtime_lock);
}
void vtime_init_idle(struct task_struct *t, int cpu)
{
unsigned long flags;
write_seqlock_irqsave(&t->vtime_seqlock, flags);
raw_spin_lock_irqsave(&t->vtime_lock, flags);
write_seqcount_begin(&t->vtime_seq);
t->vtime_snap_whence = VTIME_SYS;
t->vtime_snap = sched_clock_cpu(cpu);
write_sequnlock_irqrestore(&t->vtime_seqlock, flags);
write_seqcount_end(&t->vtime_seq);
raw_spin_unlock_irqrestore(&t->vtime_lock, flags);
}
cputime_t task_gtime(struct task_struct *t)
@ -748,13 +766,13 @@ cputime_t task_gtime(struct task_struct *t)
cputime_t gtime;
do {
seq = read_seqbegin(&t->vtime_seqlock);
seq = read_seqcount_begin(&t->vtime_seq);
gtime = t->gtime;
if (t->flags & PF_VCPU)
gtime += vtime_delta(t);
} while (read_seqretry(&t->vtime_seqlock, seq));
} while (read_seqcount_retry(&t->vtime_seq, seq));
return gtime;
}
@ -777,7 +795,7 @@ fetch_task_cputime(struct task_struct *t,
*udelta = 0;
*sdelta = 0;
seq = read_seqbegin(&t->vtime_seqlock);
seq = read_seqcount_begin(&t->vtime_seq);
if (u_dst)
*u_dst = *u_src;
@ -801,7 +819,7 @@ fetch_task_cputime(struct task_struct *t,
if (t->vtime_snap_whence == VTIME_SYS)
*sdelta = delta;
}
} while (read_seqretry(&t->vtime_seqlock, seq));
} while (read_seqcount_retry(&t->vtime_seq, seq));
}